In the current state of integrated circuit technology, an integrated circuit chip will often be tested for defects to ensure the quality and reliability of the chip or chips similar thereto. As part of such testing, the chips, also referred to as “devices under test” (DUT), may be subject to various test patterns and the DUT's response to the test patterns may determine whether the DUT passes or fails the testing.
As part of some testing protocols, the DUT is subject to electrical testing while exposed to various predetermined temperatures to simulate conditions the DUT may later experience in the field. Thermal control equipment may be used for subjecting the DUT to the predetermined temperature(s) and possibly for controlling the temperature of the DUT during the testing protocol. In general, however, the DUT's immediate thermal response to any one or more of various testing protocols is not monitored.
With respect to monitoring the temperature of a chip in the field, the chip may include a thermal diode, which may provide a temperature reading. The temperature reading may be used for ensuring the chip operates in a desired temperature range because it is generally known that a chip's temperature may fluctuate depending on processing load, chip defects, system anomalies, etc. Such temperature readings may be used for thermally controlling the chip by, for example, the use of fans or other cooling operations, or by managing the power usage of the chip.
The thermal diode, however, is not used for thermal monitoring of a DUT during testing. Even though the temperature of the DUT may be controlled during test or during field use, thermal monitoring during test may also be desired for further ensuring the quality and reliability of chips.